I believe that teaching is a profession, but that it differs from other white-collar professions in several important respects, not the least of which is the employer-employee relationship between districts and individual educators.
If there is any doubt that educators are employees, consider the case of Shelley Evans-Marshall, who was fired after teaching using books that parents found objectionable. The specifics of the case matter less than the Sixth Circuit Court's rationale in ruling for the district: Teachers' speech in the classroom is essentially purchased by school districts, and as such is not subject to First Amendment protections.
Let that sink in for a moment.
What does it mean to be both a professional and an employee? While teaching may be an art, teachers and principals are not self-employed artisans; we work for school districts, and this places on us certain obligations and expectations.
I don't think there's any inherent conflict between being a professional and being an employee, but we have to understand how being both is different from being only the former. Consider other professions such as medicine and law—while many doctors and attorneys are on staff, many others are in the more lucrative position of working for themselves, or being partners in the organization for which they work. All teachers are employees, not, as Rick DuFour puts it, "independent contractors united by a common parking lot."
Public school educators, without exception, are employees and have bosses. Teachers have principals, principals have directors, directors have superintendents, superintendents have school boards, and school boards have voters.
I find it very odd, then, that this hierarchy is not more frequently the focus of efforts to bring about improvement in education. We talk about all manner of reforms designed to hold teachers and principals accountable, yet comparatively few of these reforms attempt to capitalize on the supervisory relationships that already exist in schools.
In other professions, individual performance and market forces determine compensation and advancement (e.g. making partner in a law firm). We don't have these same forces in education, so supervisory relationships are even more important. Let's not downplay or ignore these relationships. Our failure to be good employees and good supervisors is at the heart of a significant proportion of the current public sentiment against educators.
But being a good employee does not mean simply doing what you're told; it means being true to the mission of the organization, even when this requires speaking up and challenging organizational policies and "orders" in order to uphold the interests of students.